#!/usr/bin/env python
#coding:utf-8

a = int(raw_input("请输入年份："))

def leap(a):
    if a % 400 == 0:
        return 1
    elif a % 100 == 0:
        return 0
    elif a % 4 == 0:
        return 1
    return 0

if __name__ == '__main__':

    if leap(a) == 1:
        print '这是闰年'
    else:
        print '不是闰年'
